Question

Consider a set of six infinite long straight parallel wires
arranged perpendicular to t
he plane of paper in a hexagon
as shown. The length of the each side of the hexagon
is 3 cm. what is the magnitude and direction of the
magnetic field at pont P?RA
. --------
(1) 23 u T

(2) 40 u T
(3) 60 u T
(4) 80 MT
​

Answer 1

Given that,

Length = 3 cm

A set of six infinite long straight parallel wires  arranged perpendicular to the plane of paper in a hexagon.

Suppose, the current is 6 A.

We need to calculate the magnetic field

Using formula of magnetic field

$B=\dfrac{\mu_{0}I}{2\pi\times r}$

Where, I = current

r = distance

Put the value into the formula

$B=\dfrac{4\pi\times10^{-7}\times6}{2\pi\times3\times10^{-2}}$

$B=\dfrac{2\times10^{-7}\times6}{3\times10^{-2}}$

$B=4\times10^{-5}\ T$

$B=40\ \mu T$

The  direction of magnetic field is perpendicular to the wire.

Hence, The magnetic field at point is 40μ T.

(2) is correct option.

The  direction of magnetic field is perpendicular to the wire.